You didn't need to buy a car and avoid taking public transit to risk getting and spreading COVID. Likely every single one of the places you've gone by car have been more risky than taking the train or bus.
Multiple research articles have found no link between public transport and the spread of COVID, even when looking at places like Seoul and Tokyo where transit use is much higher. The risk of catching COVID is higher at the grocery store than on a bus.
I sympathize with why you thought you needed to do that and I genuinely hope you will dispose of the vehicle once the pandemic is over. Humans are terrible at evaluating risk, and people's sudden impulse to buy a car when that's not where the risk lies is an example of this.